This invention relates to a displacement water heating apparatus for conductively heating a desired volume of water.
Displacement brewing or water heating apparatus are known in the art and provide rapid delivery of heated water on demand. These displacement water heating apparatus include a heated reservoir positioned below and in communication with a fill water basin. A fill tube is connected to the bottom of the fill water basin and extends downwardly into the heated reservoir to deliver fill water to the bottom thereof. The cooler fill water displaces heated water retained in the heated reservoir and forces the heated water out through a discharge tube for delivery to a vessel. The fill water is retained in the heated reservoir and heated to a desired predetermined temperature.
Prior art displacement water heating apparatus have a resistive heating element positioned towards the bottom of the heated reservoir for heating the fill water. Because the fill water enters the heated water reservoir towards the bottom, the fill water contacts the heating element and is quickly heated. The resistive heating element is controlled by a thermostatic control device which includes a temperature probe extending into the heated reservoir. Thermostatic control is achieved by any conventional means such as bimetalic thermostatic controls, thermocouples or thermistors.
While the displacement water heating apparatus have achieved commercial success, these devices are limited in their use for the preparation of small quantities of heated water in low frequency of use applications. For example, maintaining a large volume of water for a single use per day application is inefficient in terms of the cost of the apparatus and the energy consumption of such an apparatus. Such low frequency of use applications are readily found in the home as well as in commercial settings.
For example, individuals may desire a heated beverage as well as a serving hot cereal for a morning breakfast and require only a maximum of approximately 4 cups of heated water for such purpose. Another example of such an application of low frequency, low volume heated water use is in the hotel/motel business. In a hotel, it is desirable to provide guests with heated beverages as a morning "wakeup" beverage. Such a morning wakeup beverage requires no more than approximately 4 cups of heated water to be provided only one time in any 24 hour period.
The typical prior art displacement apparatus is inefficient for use for the low frequency, low volume heated water applications as noted above. Further, attempts to produce smaller versions of the prior art displacement water heating apparatus have failed in part due to high evaporation rates. While the evaporation rate for a typical prior art displacement heated water apparatus is approximately the same for a small or large volume apparatus, the relative effect of evaporative loss on the small volume apparatus is substantially greater. For example, a six ounce evaporative loss from an apparatus having a gallon of heated water in the heated water reservoir is minor compared to six ounces lost from a four cup apparatus.
Heretofore, applicant is unaware of any devices which have overcome these problems resulting in the present invention.